1.Development of high internal phase emulsion polymeric monoliths for highly efficient enrichment of trace polycyclic aromatic hydrocarbons from large-volume water samples.
Su R1, Ruan G2, Nie H3, Xie T1, Zheng Y4, Du F5, Li J1. J Chromatogr A. 2015 Jul 31;1405:23-31. doi: 10.1016/j.chroma.2015.05.067. Epub 2015 Jun 6.
In this work, polymerized high internal phase emulsion (polyHIPE) monoliths were prepared and applied as monolithic adsorbent materials for proconcentration of trace polycyclic aromatic hydrocarbons (PAHs) from large-volume water samples. The monolithic polyHIPE columns were prepared by in situ polymerization of the continuous phase of a high internal phase emulsion (HIPE) containing styrene (STY), divinylbenzene (DVB) and glycidyl methacrylate (GMA) in pipette tips, and the resulting STY/DVB/GMA polyHIPE monoliths exhibited highly interconnected porosity and large surface areas, making them excellent candidates as adsorbents for enrichment of trace aromatic compounds. The prepared STY/DVB/GMA polyHIPE monoliths were applied to the determination of trace PAHs in environmental water samples by combing with high performance liquid chromatography-fluorescence detection (HPLC-FLD). Under the optimized experimental conditions, the polyHIPE monoliths could effectively enrich trace 13 PAHs from 500mL of water samples, the mean recoveries at four spiked levels were ranged from 80.
2.A poly(alkyl methacrylate-divinylbenzene-vinylbenzyl trimethylammonium chloride) monolithic column for solid-phase microextraction.
Liu WL1, Lirio S1, Yang Y2, Wu LT1, Hsiao SY1, Huang HY3. J Chromatogr A. 2015 May 22;1395:32-40. doi: 10.1016/j.chroma.2015.03.066. Epub 2015 Mar 31.
In this study, an organic polymer monolithic columns, which were prepared via in situ polymerization of alkyl methacrylate-ester (AMA), divinylbenzene (DVB) and vinylbenzyl trimethylammonium chloride (VBTA, charged monomer), were developed as adsorbent for solid-phase microextraction (SPME). Different parameters affecting the extraction efficiency for nine (9) non-steroidal anti-inflammatory drugs (NSAIDs) such as the ratio of the stearyl methacrylate (SMA) to DVB monomer, column length, sample pH, extraction flow rate and desorption solvent were investigated to obtain the optimal SPME condition. Also, the permeability for each poly(AMA-DVB-VBTA) monolithic column was investigated by adding porogenic solvent (poly(ethylene glycol), PEG). Using the optimized condition, a series of AMA-based poly(AMA-DVB-VBTA) monolith columns were developed to determine the effect the extraction efficiency of NSAIDs by varying the alkyl chain length of the methacrylate ester (methyl-, butyl-, octyl-, or lauryl-methacrylate; (MMA, BMA, OMA, LMA)).
3.Detection of DNAs by Using Dual Packed Polystyrene Bead-Quantum Dots in a Microfluidic Chip.
Le NT, Kim JS. J Nanosci Nanotechnol. 2015 Jan;15(1):100-4.
The semiconductor nanocrystals (or quantum dots) have shown peculiar optical and electrical properties due to their exceptionally small size. In recent years, tremendous researches on quantum dots have been carried out. Among them, QDs as sensing media for biological assay have achieved a great progress. Recently we have reported the detection of DNAs by using fluorescence quenching of QDs after DNA hybridization. Several oligonucleotides and human genomic genes could be detected. In this report we used dual packing of polystyrene bead-quantum dots to detect different kinds of DNAs simultaneously. QDs with different emission peaks were used. Carboxylated-CdSe/ZnS QDs (emission: 525, 605 nm) could bind to microbeads of polystyrene/divinyl benzene via EDC/NHS cross-linking reaction. Polystyrene bead-QDs with different colors were packed in the channel of the microfluidic chip. The fluorescence quenching from the QDs by intercalating dye was observed after hybridization of exon 6 and 7 of p53 gene at the weir in the channel of microfluidic chip.
4.Elution profile of di-peptides on a sulfonated ethylstyrene-divinylbenzene copolymer resin column by high-performance liquid chromatography.
Guo J1, Saiki T, Thanutchaporn K, Liu W, Shimura A, Matsui T. Anal Sci. 2015;31(1):45-50. doi: 10.2116/analsci.31.45.
This study investigates the characteristics of a partially sulfonated ethylstyrene-divinylbenzene copolymer for the separation of di-peptides by high-performance liquid chromatography. Di-peptides (VE, VA, VH, VK, and VR) with different isoelectric points (pI, 4.0 to 9.7) and log P values (-1.63 to -0.72) were used to optimize the separation conditions of the columns packed with sulfonated copolymer resin. The retention factor (k) of the di-peptides on the column with a 0.81 wt% sulfo group content decreased with increasing concentrations of phosphate salts (2.5 - 20 mmol L(-1)) in the mobile phase. The complete separation of the five di-peptides was obtained with a gradient of 10% methanol containing 5 mmol L(-1) NaH2PO4 (pH 4.8) to 50% methanol containing 5 mmol L(-1) Na2HPO4 (pH 8.9) for 60 min at 0.5 mL min(-1) at 50°C. Under the optimal conditions, a good relationship between the k and pI values of the di-peptides, with the exception of VE (pI 4.